Ag402

• Name: Ag402
• URL: https://github.com/AetherCore-Dev/ag402
• Category: x402 buyer/seller middleware / Solana-USDC paywall toolkit
• Tags: solana-ecosystem ethereum-ecosystem
• Summary: Ag402 is x402 tooling, not a protocol note. It auto-pays 402 responses, throws a paywall in front of APIs or MCP servers, and settles in Solana USDC. Useful operating glue, not a new rail.
• What it does:
  • Auto-pays x402-style 402 Payment Required API responses for Python agents through ag402 run or one-line httpx / requests patching
  • Exposes seller-side and MCP-side paywall wrapping through ag402 serve, letting operators put an existing API or MCP server behind a paid proxy with minimal code churn
  • Ships setup paths for Claude Code, Cursor, Claude Desktop, and OpenClaw, including an explicit OpenClaw native skill path in addition to MCP configuration
  • Uses Solana USDC settlement while packaging non-custodial key handling, seller-no-key mode, RPC failover, prepaid payment support, and local HMAC fast paths
  • Adds CLI workflows for wallet status, transaction history, budgets, environment checks, and export tasks so the project reads as operating glue rather than one library call
• Key claims:
  • The README says Ag402 is “the payment layer for the Coinbase x402 protocol” and makes AI agents “pay for API calls automatically — on Solana, in USDC, with zero code changes,” which is a much broader claim than a thin wrapper library
  • The same materials repeatedly emphasize buyer-side zero-code operation (ag402 run, ag402_core.enable()) and seller-side zero-code monetization (ag402 serve), showing the project spans both ends of the paid-request handshake
  • The repo says Ag402 supports Claude Code, Cursor, Claude Desktop, and OpenClaw, with OpenClaw called out as a native Skill rather than only an MCP endpoint, which makes the integration surface richer than a generic MCP adapter
  • The README and repo page both stress non-custodial operation, zero telemetry, seller-no-key mode, and layered budget protection, which helps distinguish Ag402 from hosted or brokered payment services
  • The llms.txt file lays out four composable packages—open402, ag402-core, ag402-mcp, and ag402-client-mcp—which is strong evidence that the project is architected as a broader payment toolkit rather than a monolithic demo app
  • The same llms.txt documents prepaid credential flows, CLI-driven wallet management, MCP auto-installation, and environment-variable safety limits, indicating substantial operator tooling around the payment flow
  • The production examples and claims around real Solana-mainnet USDC payments suggest the project is trying to be an operating stack for real paid agent traffic, not only a developer tutorial
• Whitepaper: No canonical standalone Ag402 whitepaper or litepaper surfaced in this pass. The clearest current source of truth was the main GitHub repository, the project llms.txt, and associated first-party docs embedded in the repo; see ../whitepapers/ag402-primary-sources-2026-05-03.md.
• Sources:
  • https://github.com/AetherCore-Dev/ag402
  • https://raw.githubusercontent.com/AetherCore-Dev/ag402/main/README.md
  • https://raw.githubusercontent.com/AetherCore-Dev/ag402/main/llms.txt

Internal linkages

• Protocol base: x402
• Stronger packaging/discovery reference: 402-index

Control surface

• The leverage sits in buyer-side autopay defaults, seller-side paywall wrapping, settlement-chain choice, and the local budget / key / RPC policies that shape how the middleware behaves in practice.

• That makes Ag402 an operator toolkit around paid requests, not a protocol center.

• Keep the note pointed upward toward the stronger paid-request standards and discovery anchors.

• Last reviewed: 2026-06-03 UTC